Ketones, Urine

EPIC: LAB7120, SOFT: UKET3

Specimen Collection Criteria

Collect: A random, clean-catch, midstream urine specimen in a screw-capped container (preferred) or other sterile collection container. (Min: 1.0 mL)

Physician Office/Drawsite Specimen Preparation

Maintain specimen refrigerated (2-8°C or 36-46°F) and transport to the Laboratory.

Preparation for Courier Transport

Transport: Urine specimen, refrigerated (2-8 °C or 36-46 °F). (Min: 1.0 mL)

Rejection Criteria

• Urine volume less than 1.0 mL.
• Specimens not collected and processed as indicated.

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 4 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 7 days

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days

Laboratory

Grosse Pointe Hematology/Urinalysis Laboratory.
Royal Oak Urinalysis Laboratory.
Troy Hematology/Urinalysis Laboratory.

Performed

Sunday - Saturday.
Results available within 24 hours.

Reference Range

Negative.

Test Methodology

Automated Urinalysis Dipstick Reader.

Interpretation

Ketone bodies are the products of incomplete fat metabolism. In ketonuria, the three ketone bodies present in the urine are acetoacetic acid (20%), acetone (2%), and B-hydroxybutyrate (78%). Acetone is formed non-reversibly from acetoacetic acid. B-hydroxybutyrate forms reversibly from acetoacetic acid.

However the urine dipstick only tests for acetoacetic acid and does NOT detect acetone or B-hydroxybutyrate.

False positive results (trace or less) may occur with:

1. Highly pigmented urine.
2. Phthaleins (BSP or PSP dyes), large amounts of phenylketones, the preservative 8-hydroxyquinoline, L-dopa metabolites, and antihypertensive drugs (methyl dopa, captopril).
3. Compounds such as mesna (2-mercaptoethane sulfonic acid) that contain sulfhydryl groups may cause false positive results or an atypical color reaction.

Clinical Utility

Ketonuria may be seen in uncontrolled diabetes mellitus, vomiting, starvation, dieting, pregnancy, strenuous exercise, and certain inherited metabolic diseases with abnormalities of carbohydrate or lipid metabolism.

If it is clinically important to know whether B-hydroxybutyrate is present in increased concenetartions, recommend ordering serum B-hydroxybutyrate.

CPT Code

82009.

Test Codes

EPIC: LAB7120, SOFT: UKET3

Last Updated

03/28/2018